as the BSA Spitfire -Y is doing well, very well with its modified crank (1982) and EI (2012) topspeed and revs are steadily increasing.

the engine and framenumbers still match, I believe it is the last Spit with matching numbers, so I started out to have an extra engine prepared. when a rod drops in a othernumber engine it is a pity but not the end of the world. probably when a cheap frame turns up I will build a extra bike. but engine first.

To remove the high gear bearing, the case should be heated to 200 degrees. This takes longer than you might think, as the aluminum dissipates the heat so well. I went round and round with a propane torch, continually testing with a 200-degree temp stick. Finally, after at least 15 minutes, the temp stick melted, and you could just about push the bearing out with your fingers. Same thing on the way in, and cool the new bearing in the freezer. Fashion a drift that's the diameter of the outer race to tap it in.

lemans, If you are talking about the liitle torrington needle bearing, about an inch in diameter that the layshaft runs in, here's the deal:

First you get a 5/16ths (I think, maybe 3/8ths) carriage bolt about 2 inches long. For those not familiar with the term “carriage bolt”, it’s a bolt with a round head. Underneath the round head is a square shoulder. It is used for fastening wood. As you tighten up the nut the, force pulls the bolt head down into the wood so that the smooth round domed top is all that is sticking out. The square shoulder prevents the bolt from turning.

Anyway, grind the head of the bolt oval till you can stick it down in the hole where the needle bearing is seated. Keep grinding a little off at a time until you can stick it into the needle bearing at about 45 degrees. When you get it just right, you will be able to rotate it vertical in the cavity and the edge of the bolt head will rock behind the needle bearing. Now you just take a socket and slip it over the bolt. Put a washer on it and a nut and turn the nut down and presto…it pulls the needle bearing out of the case. It works so good it will scare you and you have made another special BSA tool for about 20 cents and a little effort.

RM11L sounds like a FAG code for a single row roller bearing in inch sizes. Possibly SKF uses the same coding, but will have the same PV (load and speed) characteristics as a similar sized bearing from another first class manufacturer. I cannot reach my SKF-book today. Maybe somebody else is faster.

RM11L sounds like a FAG code for a single row roller bearing in inch sizes. Possibly SKF uses the same coding, but will have the same PV (load and speed) characteristics as a similar sized bearing from another first class manufacturer. I cannot reach my SKF-book today. Maybe somebody else is faster.

it is indeed the single row drive side main roller bearing, in inches.

tried to look up a similar bearing in my SKF extract but it contained only different sized metric bearings.when googling the Hoffman it resulted in the "ukrainian lady's dating site".

the reason for wanting to know the dynamic load data of this bearing is to pair/match the timing-side needle roller to this bearing. if the dynamic load data of the needleroller is approx 30~50% of the roller main it should be strong enough.

when I did the conversion in 1984 I forgot to write down the skf-type number.

Anne,The SKF type is NCF xyz, a cageless cylinder bearing with one collar in the outer ring.Descriptions and calculations for the metric sizes are found on page 560 etc of this catalogue. Just choose the metric size which comes closest to the inch sizes of the RM11L.I think that will be d = 30 mm D = 72 mm with dynamic laod 84 kN static load 86.5 kN

In shipbuilding there is a caliper to check the tapered end of the propeller shaft which is supposed to match the tapered bore in the propeller hub.I needed a picture of it for some documentation. The caliper is officially called a pot-caliper.Try to find that on the WWW. A walk to the machine shop, ask the chief storekeeper for the caliper, wait for a sr. assistent storekeeper to fetch the caliper, wait for the jr. assistent storekeeper to clean the caliper, take a picture myself, thank the chief storekeeper, the sr. assistent storekeeper and the jr. assistent storekeeper, and walk back to the office turned out to be faster.

For the non natives in Dutch: A pot in our lingo is not just for cooking but also a nasty word for lesbian.

right hand engine casing back from the machine shop.machined a recess into the timing-side main to accept a SKF NKI 35/20 TN needle roller.

Do you know how they based machining of the recess ?Why did you picked up this particular bearing ?I know - the size of it is very close to the bush, but this drawn cage as a base looks not too solid for my untrained eye .

nice, I should have said I was comparing to other EI's like boyer / pazon where it doesn't reach full advance as soon the points ignition does.

the advance-curve (in reality a timed delay period) is just a liniear (ax+b)function. for the BSA it is 5drg adv @ 1000 rpm and 32 drg adv @ 3200; in between it's a "straight line". because of the microprocessor changing this curve is dead easy, new curve, new hex-file; flash the file and run. adjustable to everybody's need, wishes and best knowledge.

to optimize the BSA I'm currently working on a pressure pick-up sensor in the spark-plug, this to time the ignition in such a way that max pressure will occur just (0,001 drg) after TDC. but all this might take a while

Do you know how they based machining of the recess ?Why did you picked up this particular bearing ?I know - the size of it is very close to the bush, but this drawn cage as a base looks not too solid for my untrained eye .

I used the outside face as reference surface. where the oilpump is mounted.

I had a topic some time ago with this reference surface question. the answer then was that the cylinder-base-surface was the reference surface. both cases bolted together, then the cylinder barrel mouth is machined, then all other surfaces and axes are machined. but that is rather unusable info when remachining a bearing. so I just used the outside surface.

NKI 35/20 TN has a dynamic load capacity of 30kN which is 3/8 of the roller bearing capacity; almost 37 %. I think that's adequate.

the cases are 23 mm across and the needle roller is 20 mm. so we left a 3 mm ridge to prevent the outer bearing cage to travel sideways away from the crank.

things to do are: machining the outer timing side cover machining/grinding of the crank and some small work, camshaft bearings etc

the axial bearing has to be remade because the needle roller sits flush with the crankcase so there is no support for the axial bearing and a thicker bearing will have to be made. on the drive side the usual shims will be used.